Remote control system



Oct. 31, 1933. H HERSHEY 1,932,623

' REMOTE CONTROL SYSTEM Filed Nov. 1. 1928 s Sheets-Sheet 1 Inventor Harm Ef-Ier'shm? Oct. 31, 1933. H. E. HERSHEY REMOTE CONTROL SYSTEM Filed Nov. 2

3 Sheets-Sheet 2 Inuenlur Harry E. Hershey Oct. 31, 1933. H. E. HERSHEY 1,932,623

REMOTE CONTROL SYSTEM Filed'Nov. l, 1928 3 Sheets-Sheet 3 IEEFEETEF Ham" EHsrshs Patented Oct. 31, 1933 mesne. assignments, to Associated Electric Labh oratories, Inc., Chicago, 111., a corporation. of

Delaware Application November 1, 1928. Serial No. 316,458

' 9 Claims {s(Cl. 177-'-- 353) The present invention relates ingeneral to remote control systems, more particularly to suchsystems in which the devices in a remotely situated substation are controlled and supervised from a-dispatchers office over atrunk line ning directly between the dispatchers oflice and the substation, and the principal object of the invention, is the production of anew and im proved system of this ty'pe,-t he improvements makingthe system more reliable inoperation without increasing the cost of installation and maintenance. I

In my co-pending application, Serial No. 140,777, filed October 11, 1926, I disclose a remote control system of the type to which this application pertains, in which the selecting switch'at the dispatchers station and the selecting switch at the'substation were interconnected so as to in-'- sure that the'y'would step together. connection of the two switches was accomplished through contacts controlled by the motor magnet of the switches, and while the arrangementimsured that the motor magnet would be fully oper-'- ated on each step, it affords no means of checking the actual movement of the wipers that the motor magnet controlled. In other words, in the prior'system, should a fault develop in the arma-- ture and pawl arrangement of one of the switches and the wiper of that switch failed to step, a misoperation of a device in the substation might result. While the likelihood of such a fault developing in a switch mechanism is very small, in certain instances it is desirable to positively check the operation of the switches through the switch wipers and bank contacts to be absolutely sure that the substation switch is standing upon the same contact 'in its bank as the dispatchers' station switch before any operation is performed. Accordingly, as an objector the present invention I have provided new and improved circuit arrangements and swtches through the operation of which a positive check of the position of both the substation switch'and the dispatchers switch is obtained prior to the closing of any operating aligned the closing of the operating circuit is positively prevented.

In my co-pending application I make use of a The inter-- circuits, and if the switches are not properly This switch mechanism is pro-{- the present invention I have modified and iin proved this switch structure by including a pawl arrangementsuch that the wipers of the switch are advancedone step whenthe magnet energizes and'anotherf step when the magnet deen- 0 ergizes, I make useof the doublestepping action of 'the switch toicontrol the'checking circuits so that when the selecting switch at the dispatchers station isfi'nall'y' brought to rest on the desired contacts, circuits are prepared and com- 5 pleted through the substation switch to check the position of the latter switch'toinsure that that switch also rests upon the corresponding contacts. J

' Other objects or the invention, not specifically mentioned here, will be apparent from a reading of the detailed description and, claims which follow. The drawings comprising Figs. 1 to 3 show in Figs; 1 and 2 circuit representation of my invention while Fig. 3 shows the mechanical arrangement of the improved switch that I employ. When Fig. 2 is laid to the right of Fig. 1 with correspondingly numbered lines in alignment, these figures show by the, usual circuit symbols sufiicient apparatus to enable a'clear understanding of my invention. The equipment shown in Fig. 1 is thatplocated at the dispatchers' oifice and comprises the control keys-K1 and K2 and'the' signal lamps 51, to 55, inclusive, through the operation of which the devices at' the substation are controlled and supervised. The dispatchers station is also equipped with the selecting switches S1 and S2, S2 being employed in the sending operation under the control of the key K1 and other similar keys, not shown, the switch S1 being employed'to check the operation ofthe system- The dispatchers station'is connected to the substation by the trunk conductors'64, 65, 6G, and 67. Conductor 66 can be omitted and the neutral point of batte'ry grounded if no objectionable groun 1i potentials are, encountered; v I I Fig. 2 shows the equipment inthe substation, comprising the selecting switch S3 which is stepped by the sender switch'S2 oi the dispatchersstation to select a particular device, such as the circuit-breaker CB. Polarized relay 15in the substation is operated .by the key K2 and other similar keys, not shown, to apply operating potential to 'the selected device to open or close it. The circuitbreaker CB which is shown by way of example Only; comprisesan 'electromagnetic circuit breaker'having an open and closed. position, which breaker latches in its closed position through the operation of the latch 101. The magnet 20 is employed to close the breaker and the magnet 19 to unlatch it and permit it to open by spring action. Attached to the circuit breakers are the contacting points 49 and 50 through which the position of the circuit breaker is supervised in a manner which will be pointed out hereinafter.

In Fig. 3 I show the mechanical details of my improved switch mechanism, which will be recognized as the rotary line switch bank 311, the rotary line switch frame 315, bearing the magnet 312 and the armature 301. I have modified the standard switch mechanism by equipping the armature 301 with the double pawls 302 and 303. The pawl 303 has a face 304 which engages the teeth of the ratchet wheel 305,'the shape of this pawl being such that the tooth is enaged when the armatureenergizes and moves the armature and pawl to the right. When the magnet is completely energized the pawl 303 is resting against the stop 308, the wipers 310 and 310' have been moved one step and one of the wipers, have been moved into engagement with the next bank contact setfand the pawl 302 has been backe'd'up away from the stop 307'. Pawl 302 'is now engaging a tooth of the ratchet wheel 305, and, when the magnet 312 is deenergized'and the armature 301 moves to the left under the, power of spring 314, the pawl 302 advances the ratchet wheel 305 another step in a clockwise direction to advance the wipers 310 and 310' whereby one of the wipers are ad-- vanced into engagement with the next set of contacts in their bank. Each'wiper, such as wipers 310 and 310, has access to a diiferent set of bank contacts and the wipers are, positioned directly opposite each other so that'when wiper 310 is engaging its contacts, wiper 310 is. out of engagement with its contacts. The wipers, therefore, engage their contacts only duringone half of their revolution. In this manner, only one wiper at a time will be in position to engage its bank contacts and although each wiper has access to only twenty-five bank contacts, the arrangement of the wipers and bank contacts are such as to be the equivalent of a 50 point switch with a single wiper. The wipers are held in the position in which they are set by the pawls by the action of the retaining spring 309 which engages the teeth of the ratchet wheel 305. Thus it will be seen'that by the interaction of pawls 302 and 303 the wipers 310 and 310' will be advanced two steps for each energization and deenergization of the motor magnet. In Fig. 3 I have opened sections of the frame 315 to permit a clearer showing of the ratchet wheel 305 and the pawl faces 304 and 306. The switch S3 of ,Fig. 2 corresponds in mechanical construction to the switch. shown in Fig. 3, the wipers 86, 88, 90, and 92 of S3 ,corresponding to wipers, such as wiper 310; and wipers 8'7, 89, 91, and 93 of S3 corresponding to wipers, such as wiper 310'. The motor magnet 18 ofS3' corresponds to the magnet 312 of Fig. 3. a 1

Throughout the drawings I have shown a plurality of symbols comprising a plus sign within a circle for positive battery, and a negative sign within a circle for negative battery, and a letter N within a circle for neutral. At the extremities osaeas the actual connections to avoid an unnecessary complication of the drawings.

In the operation of the system the dispatcher throws the selecting key such as K1 to select the particular device that he desires to operate. Responsive to the operation of this key the sender S2 transmits impulses out over the conductor 64 tostep the selecting switch S3 in the substation through the control relay 14; The switch S3 is the double stepping switch shown in Fig. 3 of the drawings. When the magnet 18 of this switch is energized the wipers are advanced one step into engagement with the first contact of their banks. When this contact is engaged a circuit is'completed through wiper 86 or 87 to transmit an impulse back over conductors 65 and 66 to operate the switch S1 in the dispatchers station. When the sender opens the circuit to the substation to'permit the magnet 18 of the switch S3 to deenergize the wipers are advanced another step and the circuit of the switch S1 is thereby opened to permit that switch to fall backand advance its wipers one step. The switches S1 and S2 are not double acting switches, and their wipers are not advanceduntil theirrespective motor magnets are deenergized. The selecting keys, such as K1, lead to the bank of the switch S2 over which wiper 84 rotates and when the control key is in its normal position the corresponding bank contact is connected toneutral battery. When the selecting key K1 is thrown to its operated position neutral is removed from the bank contact associated with that key and when the wiper 84 engages, that contact impulsing stops and the switches S2, S3, and S1 are brought to rest upon the corresponding contacts in their banks. If all of theswitches have operated properly, the circuit through the banks of switches S1 and S2 over which wipers 81 and 85, respectively, rotate, permits the energization of relays 1 and 2 and the operation of control key K2 is thereby made effective to control the polarized relay 15 at the substation. The operation of polarized relay 15 at the substation closes a circuit to open or close the selected device such as circuit breaker CB. The movement of the device changes the potential picked up by spring 49 to complete a circuit back through wiper 93 and the conductor 67 to operate the supervisory polarized relay i at the dispatchers station. 'The operation of this relay alters the lamp signals 52 to 54, inclusive, to indicate the new position of the circuit breaker CB.

When the dispatcher has completed the operation and supervision of the device CB he restores the key K1, thereby reapplying neutral to the bank contact engaged by wiper-84 and stepping is resumed. The stepping continues until the wipers reach their normal position in which the switches are brought to rest.

The automatic movement of the circuit breaker CB operates the switches to cause them to move their wipers over their bank contacts to supervise the position of all of the circuit breakers in the substation in identically the same manner as explained in detail in my above referred to 00 pending application.

Having thus described my invention in general, I will. now proceed with a detailed description of its operation. Assume that the dispatcher desires to close the circuit breaker CB. The key K1 is associated with the circuit breaker CB and connected by conductor 62 to the first working contact in the bankengaged by wiper 85 of the switch S1 and by conductor 61 of the first bank contact in the bank over which wiper 84 rotates,

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and by conductor 60 to the normal position contact of the wiper 84. Other selecting keys, not shown, are connected by similar conductors to the corresponding bank contact of the switch to permit controlling of other circuit breakers or devices. When the key K1 is thrown, a circuit is closed from neutral through springs 20 and the conductor 60, through the normal position and wiper 84, spring 33, through the winding of relay 6 to negative. Relay 6 is equipped with a copper slug on the armature end ofits core, shown in the drawings by the shaded portion at the upper end of its core, and is therefore slightly slow to operate. After "a brief interval, relay 6 pulls up and closes a circuit from neutral through springs 37, conductor 64, through the winding of relay 14 to negative, with a multiple circuit through the winding of relay 7 to negative. Relays 14 and 7 pull up over this circuit, the former to close at springs 43 the obvious circuits for relay 13 and magnet 18, to energize that relay and that magnet. Relay 7 at springs 39 closes a circuit through springs 38 to the magnet 5, to energize that magnet. Relays 7 and 13, being equipped with a copper slug on the heel end of their cores do not immediately deenergize when the circuit through their windings is opened. The energization oi the magnet 18 advances the wipers 86 to 93, inclusive, one step bringing the wiper 87 into engagement with its first bank contact to which contact conductor '70 is connected. This completes a circuit over conductor through spring 42 and its make contact, through the conductor 65, through r spring 40 and its make contact, through the winding of relay 8 to negative. Relay 8 energizes and at springs 41 completes a circuit from neutral through conductor 69 to the magnet 9 to negative, to energize the magnet 9.

" With magnets 5, 18, and 9 energized, switches S1 and S2 are in the position to advance their wipers one step and switch S3 has advanced its wipers one step. The energization of magnet 5 at springs 33 opens the circuit of relay 6, that relay falling back after a brief interval. At springs 37 relay 6 opens the circuit of relay 14 which falls back immediately and at springs 43 opens the circuit of the magnet 18 which falls back and advances the wipers 86 to 93, inclusive, one step into engagement with their second bank contacts. The deenergization oi relay 14 opens the, circuit of relay 13 however that relay did not immediately deenergize. The deenergization of relay 6 at springs 38 opens a'point in the circuit of magnet 5, to permit that magnet to deenergize and advance the wipers 84 and 850m step into engagement with their first bank contacts.

The movement of wiper 87 from its first to its second bank contact opens the circuit of relay 8, permitting that relay to fall back and open the circuit of magnet 9 which falls back and advances the wipers to 83, inclusive, one step into en-' gagement with their first bank contacts. Lamp 51 is lighted over wiper 80 in an obvious circuit to indicate the position of the switch S1.

Since the key K1 is thrown, and springs 21 operated, neutral battery has been removed from conductor 61 and the wiper 84 does not again complete the circuit oi relay 6. After a'briei interval relays 7 and 13 restore, to prepare the operating circuit.

If the switches 81 and S2 have stepped properly, a-circuit is completed from neutral through springs 22, conductor 62, thence over parallel paths; the one through the wiper 81 and its first bank contact to the winding ofrelay 2 to negative; the other through first bank contact and wiper of the switch S2, through the winding of relay 1 to negative. Relays 1 and 2 energize if the circuits are completed, and at springs 28 to 31, inclusive, prepare for operation of the selected device by extending positive and negative battery through the resistances R3 and R4 to the springs 24 and 25.

Since the circuit breaker CB is now assumed to be in its open position the next operation is for the dispatcher to close it.

If the relays 1 and 2 have been operated by the correct setting of the selecting switches, the throwing of key K2 upward to operate springs 23 and 24 closes two circuits, one circuit for the change lamp 52 by way of springs 23 and the resistances R5 and R6 to indicate which device is to be operated and the second circuit from positive battery through resistance R3, springs 28 and 30, springs 24, conductor 76, the first bank contact and wiper 82, conductor 68, spring 40 and its break contact, conductor 65, spring 42 and its break contact, through the winding of polarized relay 15 to neutral. Relay 15 energizes over this circuit ,movlng its armature 44 to the left to close a circuit from neutral through spring 44 and its left hand contact, wiper 91 now engaging the contact to which conductor 73 is connected, through the winding of the operating solenoid 20 to negative. Solenoid '20 operates moving the switch to close the contacts 100 and to move the springs 49 and 50 away from their left hand contacts and into engagement with the right hand contacts. The operation of spring 49 alters the potential upon conductor 74 from positive to negative, completing a circuit through wiper 93, the conductor 67 and'the wiper 83 through the winding of polarized relay 4 to neutral.

Relay 4 operates its armature spring 32 over against its right hand make contact completing a short c'rcuit around lamp 52 and completing a circuit from negative through resistance R6, through signal lamp 53, through springs 32, through resistance R5 to positive battery. Lamp 52 is'extinguished and lamp 53 glows to indicate that the circuit breaker is closed. The operation of springs 32 away from the left hand make contact opens the circuit of lamp 54 which had been burning over the circuit from negative through resistance R6, spring 32, the lamp 54, through resistance R5 to positive.

The dispatcher having noted that the breaker is in its closed position releases the key K1 thereby reapplying neutral to the conductor 61'and the bank contact upon which wiper 84 is resting to reenergize relay 6 and the other relays employed during the setting of the switches. Switches S1, S2, and S3 will be stepped over their banks into engagement with their normal position contacts if all of the other selecting keys are in their normal positions. When all the switches and relays return to their normal positions relay 3 energizes over the following circuit: negative battery, relay 3, normal "contact engaged by wiper 82 and said wiper, conductor 68, resting contact of armature 40 and said armature, conductor 65,

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from neutral through the springs controlled by armature 50, conductor 75, springs 45, winding of relay 16 to negative, permitting the relay 16 to fall back. Relay 16, upon falling back, closes a circuit for relay 1'? through armature 46, through the home position of wiper 93, conductor 67, home position of wiper 83, through the winding of relay 10 to negative. Relays 10 and 17 energize over this circuit, the latter locking itself independently of relay 16 at springs 48 and closing the circuit of relay l6 and springs 4'7. Relay 16 pulls up, locks itself to conductor which by this time has been returned to neutral by the arrival of the circuit breaker in its opposite position.

In the dispatchers ofiice the energization of relay 10 closes a circuit for relays 11 and 12, which energize after a brief interval. At springs 34 relay 12 applies neutral to the home position engaged by wiper 84 of the selecting switch to complete a circuit through springs 33 and the relay '6 to negative. This energizes the relay 6 to start the stepping of the switches, which are stepped once over their banks to supervise the position of each of the devices in the substation. Since the conductor 67 extends from wiper to wiper of the switches S1 and $3, the supervision takes place while the switches are in motion and when the switches again arrive in their normal position the signal lamps are set to indicate the position of the device. This arrangement is exactly the same as that shown in my previously mentioned co-pending application and need not be further explained at this time.

Having thus described my invention, what I consider to be new and desire to have protected by Letters Patent will be pointed out in the appended claims.

What is claimed is:

1. In a remote control system, a selectingswitch, a sender, a preselecting means for operating said sender to transmit impulses to said selecting switch, means for stepping said selecting switch two steps for each of said impulses, a checking switch, means controlled by said selecting switch for stepping said checking switch one step for each two steps taken by said selecting switch, and means jointly controlled by said sender and said checking switch for checking the position of said selecting switch.

2. In a remote control system in which a sender switch is operated under the control of a key to take a particular number of steps and to transmit a corresponding number of impulses, a selecting switch having wipers, means for advancing said wipers two steps responsive to each of said impulses to select a device on each alter nate step, a checking switch, means for advancing said checking switch one step responsive to each of the other steps taken by the selecting switch for checking the operation of said selecting switch, and means energized through said sender and checking switches only if said sender and checking switches have taken the same number of steps for preparing an operating circuit for operating the selected device.

3. In a remote control system, a trunk line, a sender and a checking switch at one end of said trunk line, a selecting switch at the opposite end of said trunk line, means for operating said sender to transmit a particular number of impulses over said trunk line, means responsive to each of said impulses .for operating said selecting switch two steps, means controlled by the operation of said selecting switch for selecting a device on one step and for operating said checking switch on its other step for each impulse, and means controlled jointly by said sender and checking switch for checking the position of said selecting switch.

4. In a remote control system, a selecting switch having a plurality of positions including alternately disposed checking and operating positions, means for transmitting impulses to said switch, means responsive to each of said impulses for moving said switch first into a checking and then into an operating position, a checking means, and means controlled through each checking position of said selecting switch for operating said checking means to check the position of said selecting switch, and devices supervised and controlled through each operating position.

5. In a remote control system, a sender switch having a bank and a wiper registering therewith, a selecting switch having a bank and a wiper registering therewith, means for operating said sender to transmit impulses to said selecting switch to operate it, a checking switch having a bank and a wiper registering therewith, multiple connections between the bank of the checking switch and the bank of the sending switch, means for stepping the checking switch, a circuit for operating the said stepping means including the wiper of the selecting switch and bank contacts of the selecting switch, said circuit alternately closed and opened responsive to the stepping operation of the wiper of the selecting switch for operating the said stepping means, and means controlled through saidmultiple connections and the wipers of said sender and checking switches for checking the position of said selecting switch.

6. In a remote control system in which a sender switch is operated under the control of a key to take a particular number of steps and to transmit a corresponding number of impulses; a selecting switch, a plurality of devices, means for advancing said selecting switch two steps responsive to each of said impulses to select a device on alternate steps, a checking switch, means for advancing said checking switch one step responsive to the other steps taken by the selecting switch for checking the operation of the selecting switch, means operated through said sender and checking switches only in case said sender and checking switches have taken the same number of steps for preparing an operating circuit for the selected device, and an operating key for closing said prepared circuit to operate the selected device.

7. In a remote control system in which a sender switch is operated under the control of a key to take a particular number of steps and to transmit a corresponding number of impulses, a selecting switch, a plurality of devices, means for advancing said selecting switch two steps responsive to each of said impulses to select a device on alternate steps, a checking switch, means for advancing said checking switch one step responsive to the other steps taken by the selecting switch for checking the operation of the selecting switch, a

plurality of operating keys each one of which I said potential to complete the operating circuit of the selected device.

8. In a remote control system in which a sender switch is operated under the control of a key to take a particular number of steps and to transmit a corresponding number of impulses, a selecting switch, a checking switch, a plurality of devices, means for advancing said selecting switch two steps responsive to each of said impulses to transmit an impulse for each alternate step and to select a device for each of the other steps, means responsive to said last mentioned impulses for advancing said checking switch to check the operation of said selecting switch, and means operated through said sender and checking switches for preparing an operating circuit for the selected device.

9. In a remote control system, a trunk line,

an impulse sender and a checking switch at one end of said trunk line, a selecting switch at the other end of the trunk line having alternately disposed selecting and checking positions, means for operating said sender to transmit a desired number of impulses over said trunk line, means responsive to each of said impulses for moving said selecting switch from one selecting position to the succeeding selecting position through. the intermediate checking positions, devices each selected at the respective selecting positions of the selector switch, means controlled by the movement of the selector switch over each checking position for operating the checking switch and means controlled jointly by the sender and checking switch for checking the position of the selector switch.

HARRY E. HERSHEY. 

